1. Field of the Invention
The present invention relates to a method of manufacturing a friction plate used for an automatic transmission. More particularly, the present invention relates to a method of drying and curing adhesive.
2. Description of the Related Art
When manufacturing a friction plate by making a friction member adhere onto a core plate, in conventional, an adhesion face is made to be rough for increasing an adhesive strength of the friction member, and further, as a pretreatment process to be conducted before degreasing and cleaning, sand blasting, degreasing by alkaline detergent, pickling by sulfuric acid and neutralization by a neutralizer is conducted.
However, when blasting is conducted on the core plate, the core plate tends to be deformed easily. Further, the peripheral devices tend to be abraded by powder used in the process of blasting. Further, importance has been recently attached to the environmental problems. Therefore, it is desired to develop a means for replacing the above pretreatment means.
In order to solve the above-mentioned problems, various inventions, for example Japanese Patent Unexamined Publication no. JP-A-2002-327782, have been accomplished.
FIG. 6 is a view showing a flow 10C of the conventional manufacturing process described in the above related art. Reference numeral 30 denotes a surface roughing step in which the surface of a core plate is roughed. In this surface roughing step, the core plate 1, which has been punched into a predetermined shape, is supplied to the conveyer 32 as shown by the arrow 31 and then one side of the core plate 1 is buffed by the buffing roller 34. Successively, the core plate 1 is attracted by the conveyer 33 which is magnetized, and the other side of the core plate 1 is buffed by the buffing roller 34. After that, the core plate 1 is demagnetized by the demagnetizer 35 and sent to the cleaning step 40.
Reference numeral 41 defines a rough cleaning step, reference numeral 42 defines a finishing cleaning step, and reference numeral 43 defines a drying step. Reference numeral 44 defines a shower of cold or hot water, reference numeral 45 defines a nylon brush, reference numeral 46 defines a finishing shower of cold or hot water, reference numeral 47 defines a nozzle of compressed air for removing water, and reference numeral 48 defines a roller conveyer for conveying the core plate. When the core plate is buffed as described above, a surface thereof is slightly scraped so that the adhesive face can be roughed and oil adhered thereto can be simultaneously removed. Therefore, it is possible to omit the steps of alkaline cleaning and pickling treatment.
Reference numeral 50 defines an adhesive coating step, reference numeral 51 defines an adhesive supply pipe, and reference numeral 52 defines an adhesive tank. A set of large and small rollers 53, 54 is arranged at the upper and the lower position. Adhesive is supplied to position defined between the upper rollers 53, 54, and the lower rollers 53, 54 are dipped in the tank 52. Therefore, adhesive is held on the surfaces of the large rollers 53 so that the adhesive can be coated on both faces of the core plate 1 which passes through between the large rollers 53, 53. The small rollers 54, 54 have a function of adjusting a quantity of adhesive attaching to the large rollers 53, 53.
Reference numeral 80 defines a drying and curing step of adhesive. A blast of hot air having predetermined temperature is blown to the core plate 1, on which the adhesive is coated, and the adhesive is dried and cured in the furnace 85.
The core plate, on which the adhesive is dried and cured, is conveyed as shown by arrow 71. On the other hand, the friction member, which has been punched into a predetermined shape, is conveyed as shown by arrow 72. The core plate and the friction member are put on each other and conveyed to the main adhesion step 90.
Reference numeral 91 defines a hot press. The core plate, on which the adhesive is coated, dried and cured, and the friction member are put on each other and formed into the piled body 3. The thus formed piled body 3 is heated and pressured by the hot press 91. In this way, the complete friction plate 4 can be formed.
Even in the case of the above-mentioned conventional example, consideration is given to the environmental problems. Further, concerning the method of coating the adhesive, such a problem is solved in the conventional example that the adhesive attaches to an inner circumference of the core plate and clearance of the core plate with respect to the opponent member can not be maintained accurate. However, in the conventional method of coating the adhesive, the following problems may be encountered. Since a hot blast furnace is used for drying and curing the adhesive, it is necessary to provide a large space in which the apparatus is installed and further it takes no less than four minutes to dry the adhesive.